First I should note that I assume GNOME or KDE probably does a great job automounting the Canon PowerShot A590, or at least getting the pictures off of it. Not having GNOME or KDE, however, I'd like to do it from the command line.

Lots of cameras will automatically be recognized as USB mass-storage devices. If this is your camera, great. Just find the camera with "fdisk -l" (as root), and mount it. Then use it like any other mounted drive. Unfortunately, The PowerShot A590 does not work that way (I think it may use PTP - Photo Transfer Protocol). For these kinds of devices, "fdisk -l" yields nothing. You can, however, see that the system took note of the camera if you look at /var/log/messages

I saw gphoto2, but gphotofs sounded more interesting, so I tried it. Having tried it, I advise against it. It does kind of work, but I found it to be buggy (especially about permissions), and not nearly as nice to work with as gphoto2. If you choose to try it, the short man page should explain everything you need (man gphotofs).

gphoto2, however, is really a joy to work with. It's incredibly simple, and works really well. Here are the basics:

## Install gphoto2 (this needs to be done as root)
apt-get install gphoto2
## Plug the camera in via USB, make sure you're in Playback mode (as opposed to Shooting mode), and turn it on
## Some people recommend this step to recognize your camera, but I found it unnecessary
gphoto2 --auto-detect
## List what pictures/videos are on the camera
# The list will be numbered - later you can use those numbers to download specific photos
gphoto2 -L
## Download all pictures/videos
gphoto2 -P
## If you just want thumbnails, you can get them with
gphoto2 -T
## If you have feh installed, you can easily view the thumbnails with
feh -t .
## Download only a particular picture (or a range of pictures) using the numbers from the list produced by "gphoto2 -L".
gphoto2 -p 10
# obviously you can select any number here.
## That's pretty much all of the commands I ever need to use. There's lots more that gphoto2 does, however, and it's well-documented in
man gphoto2